The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge in Australia or elsewhere as at the priority date of the application.
Trucks typically comprise a chassis having a cabin and an area for placing cargo or equipment. The area for placing the cargo or equipment comprises a tray adapted to receive and contain the cargo. In dump trucks the trays are pivotically connected to the truck frame allowing tilting of tray for releasing the load.
The trays of the trucks comprise a tray bed and a canopy.
The tray bed defines a carrying surface for placing of materials and goods. Also, the tray bed comprises side walls for containment of the materials or goods within the tray. During operation, the carrying surface is subject to large tensile loads and weight due to the material or goods carried in the tray beds. The large tensile loads and weight may permanently damage the carrying surface and side walls of the tray beds. Also, the tray bed or the canopy may be perforated by heavy loads which fall on the carrying surface of the tray bed or the covering section of the canopy during loading of the tray.
The canopy of the tray defines a roof like structure including a covering section which extends outward from the tray bed towards the front end of the truck. The canopy covers the truck cabin to protect the cabin and the truck driver located inside the cabin from materials that may fall on the canopy instead than into tray bed during a loading operation.
The tray bed as well as the canopy must be adapted to carry heavy loads. Therefore, the trays are manufactured using materials that can withstand the large loads and weight to which the trays are subjected. This makes the trays heavy as well as expensive.
During continuous operation of the trays the heavy loads and irregular shaped materials may permanently damage the trays. Also, for example heavy loads falling on the trays during filling of the tray may perforate the surfaces of the tray bed and/or the canopy. After perforation or permanent damage of the tray, the tray must be refurnished or disposed of.
Refurbishment or disposal of the tray due to permanent damage is expensive and a waste of materials.
It is against this background that the present invention has been developed.